Safety attachment for valves



'TNO Modem' J. A; GRIFIITHS.

SAFETY ATTACHMENT FDR VALVES. 467.

Paten-ted June 1, 1897.

HHH IIIH made separable from the valve.

lsponding parts in the several figures.

Enron.

PATENT v t'AtIns A. ennvrrrns, or PHILADELPHIA, PENNsYLvANIA.

SAFETY ATTACHMENT FOR VALVES.

SPECIFICATION forming part of Letters Patent No. 583,467, dated June l,1897. Application filed May 2,1895. Serial No. 547,S54. v(No model.)

To @ZZ IUI/,0712, it may concrrn.:

Be it known that I, J AMES A. GRIFFITHS, a citizen of `the UnitedStates, residing in the city and county of Philadelphia, State ofPennsylvania, rhave invented a new and useful Improvement in SafetyAttachments for Valves, which improvement is fully set forth in thefollowing specification and accompanying drawings.v i

My invention consists of anovel construetion of safety attachment forValves which are Aliable to be subjected to high pressures, provisionbeing made for allowing a suitable plate or diaphragm to burst when acertain maximum degree of pressure has been reached without injuring thevalve orits adj uncts.

It also consists of novel means of packing the stem of said valve.

It further consists of novel details of construction, all as will behereinafter set forth.

Figure l represents a Vertical sectional view of a safety attachment fora valve embodying my invention. Fig. 2 represents a perspective View ofa portion of the body of said valve, showing the safety attachment andits adjunct-s removed and the manner of assembling the same. Fig. 3represents a vertical sectional view showing the safety attachmentSimilar letters of reference indicate corre- Referring to the drawings,A vdesignates a valve, the same having the body B, the inlet C, andtheoutlet D, adjacent to which latter is located thevalve-seat E, withwhich the head or valve F is adapted to Contact, the Same being suitablyconnected to the lower threaded portion J of the ystem K, which latteris provided with a hand-wheel or similar device.

L designates a helical or spiral groove in that portion of said stem Kwhich is in con-r tact with the packing M of the stufling-box N, saidpacking being held in position between a ring or washer P, which abutsagainst a shoulder N at the lower portion of said stuffing-box and thegland Q, which latter is held in position by the cap-nut R, throughwhich said stem K passes, said cap-nut being adapted to bein contact atits lower portion with a lock or check nut S, it being evident thatfsaidgroove L may be a helical or spiral ridge, if desired, its functionbeing the same in either instance.

T designates a threaded boss which is attached to the valveebody B andhas a passage U extending therefrom which communicates with the maininlet C, it being noticed that said port U communicates with said inletalways at a point below said valve-seat E, so that the maximum pressureis always in said passage U,whether the valve is open or closed.

' V designates a plate or diaphragm, which may be made of copper orother suitable material and which has in contact therewith a ring orwasher W, which may be of paper or similar material, said plate andwasher being held in position by a cap X, having a threaded portionengaging said boss, and the recess Y therein, from which latter extendat an angle thereto the outlet-ports or vents Z, it being noted thatsaid ports Z are out of alinement with said plate V or passage U, sothat it will be impossible for said plate to be readily Apunctured ordestroyed from the exterior by any one tampering with said cap.

-It will be noted that by the employment of the Washer W' in thelocation and manner described the diaphragm V is caused to be removed ashort distance from the end of the boss T, and thus to cause a greaterportion of its surface to be exposed to the excess of pressure than if.no washer was employed, thereby enabling said diaphragm to be quicklyacted upon and burst whenever said excessv of pressure is reached.

In Fig. I have shown the safety attachment made separable from thevalve,1 A designating the latter, having the outlet D, as before. rlhelower portion A of said Valve is threaded and is adapted to engageasimilar threaded portion 0/ the plug l5', the'lower end of the latterbeing also threaded, said plug having the inlet-passage D', vinto whichleads the passage E', whose outer end is closed by means of thediaphragm V, washer W, and cap X, having therein the recess Y. and theports Z substantially the same as has been described with reference toFig. l, the function of the parts being the same in each instance.

The operation is as follows: Whenever the pressure entering the inlet Cfrom the receptacle to which the valve is 'attached exceeds IOO the4safety-point, the plate Y will burst tion only ol' the plate V, which,being of inexpensive material, can be readily replaced by removing thecap X', the valve and its adjuncts remaining thus nninjured, as is evident.

with the packing )l will eausean exceedingly el't'ective joint to bemade between the stem and the packing and will reduce the liability ot'lez'lkage to a minimum, it being understood -`that the extent ot'movement required to open valves ofrthis character is very slight andthat there is'therefore no injurious tearingor dsintcgratiug et'eetlproduced upon the paoloing, it having been found in practice that muchbetter ell'cets are attained when the valve-stem is grooved in themanner described than when the stem is ol uniform diameter throughout.

ly forming the'heliealor spiral groove L en that portion of the stem liwhich passes through the packing )t there is formed a tighter joint orpacking in the box N than would be the ease it' thc stem K were smooth,and when the stem l( is rotated this tightjoint is not disturbed, but,on the contrary, is keptinthedesiredcondition. Whenasmooth `ltom iscaused to traverse the ,packing-thc bearing-surface ol' the packingbecomes worn amLhardened, thus loosening the connection between the stemand packing. \Vl1en my improved siem is used, the packing issultieiently agitated or rubbed to prevent the smoothnessl and hardnessordinarily occa.- sioned by the rubbing` ola polished or smooth stemupon the packing.

Again, by locating the safetylvalvewith its plate or diaphragm so thatits inlet U is in co1nmunication with the inlet C ofthe main valve belowthe valve lf the maximum preslsure on the vessel to which the valve F isattached is always exerted upon the diaphragm rlhe helical or spiral'groove or ridge. in the stem l\' being tightly in engagement- U beforeor at least at the same time the pressure is exerted upon the valve F.Hence it follows that before the excess of pressure can burst the vesselor impair the valve F the weak membrane or diallhragm V will burst. Thediaphragm Y thus controls the pressure exerted upon the valve F.

Having thus described my invention, what lclaim as new, and desire tosecure byLetters Patent, is

1.`A ln a earbonic-acidgas-and similar reservoir, a casting providedwith a main valve, said casting havinginlet and outlet passages therein,and provided with a projection having an inlet-passage co-nnnunicatingwith the inlet of said mainvalve but so located be neath the sea-tiefsaid valve as to always be unaffected by said valve and a safety-valvecomprising a cap having a diaph'agm mounted therein and said capdetachably applied to said project-ion, substantially as and for thepurposes described.

2. In a carbonie-acid gas and similar reservoir, a casting provided witha main valve, said casting having inlet and outlet passages at rightangles to each otheraud aprojeetion provided withan internal passagecommuni eating with the inlet of said main valve and a safety\'alveattaclnnent, comprising a cap and a diaphragm mounted therein, saidsafety-valve being so located below the seat ot' said main valve as tobe always unattected by said valve and said dialihragm normally closingthe outlet or recess Y, in communication as and lor' the purposesdescribed.

il. 1n a valve forcarbonie-aeid gas and simi- Vlar reservoirs, apacking-box, a stem having a spirally ridged'or lgrooved portion adaptedto traverse said box, and a packing located in said box andcloselysurroumling said stem, substantially as and for the purposesdescribed.

lminis A. laurm'rns. itnesscs:

ith ports '/l, of said cap, substantially

